yes, don't buy the black ones that say they are for BMW, they use a new type of connector that doesn't exist on the coupe.
Horn location
- Thread starter e9Leveque
- Start date
Mine don’t work either and are on my list of things I have yet to get to .
I am hoping that the screws on mine aren’t seized into the housing.
I have supplied 12v directly to mine and they don’t work, so it’s not anything on my car that is preventing mine from working.
The last time she was on the road was 1989 so they are probably just seized up from lack of use.
I’m hoping she’ll be back on the road by next summer , fingers crossed!
( I have had that same thought for a few years now though
)
curious about 12v going directly to your battery. all horns have power directly from the battery to the relay - when the horn button is pressed, it completes the circuit and diverts power to the horns ... making a sound as long as the ground wire is secure (after the horns)
Mine were off the car.
So I just connected them to a battery on the bench.
I like to test components and prove to myself that they work before refitting them.
as long as the horn was grounded, it should sound when you apply power ... if not, then it needs to be cleaned or replaced. i took the quick approach and bought 2 from Amazon for 30 bucks. i am replacing the wiring harness from the relay to the horn, as well as replacing the ground wires from the horn (and lights). i have bought new spade connectors and the clear sleeves.
jmackro
Well-Known Member
If that is the case, then I wouldn't replace the whole harness just to get the horns to work. The horn circuit is about the simplest one on an e9 (and pretty much any car of that era - they're probably computer-controlled on modern cars).
Ok, an update (and thanks everyone for going along on this journey with me). Turns out that my 12V tester was being nonfunctional and wasn’t outputting enough power to directly sound either horn out of the car. Hooking directly to a small 12V worked. New tester now will sound each horn, and if I power across the relay I get two-tone horn sound! So now moving up the chain, when I take out the horn button, I only see one wire leading from it down the steering shaft. I would have figured that there needs to be a ground on the other side of this switch but not seeing it. That’s also what the wiring diagram shows, so once again I’m confused. I wish I were better at wiring. As a neurosurgeon you’d figure I’m into the wiring (brain) but have gravitated more towards the engineering/mechanical side of the field (spine). Guess my work reveals my weaknesses…
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whomever was here before me decided that brown and green is close enough to brown and yellow that it shouldn’t make a difference, right?
I took the suggestion above and ordered an old wiring harness to try to keep these colors correct so I can actually figure out what the hell is going on here. I think my pain is making me realize I better make it simple for the person who might follow me. As it is this just isn’t cool. But I think I figured out the horn issue - there’s nothing connected to that spade connector on the backside of the horn assembly
I took the suggestion above and ordered an old wiring harness to try to keep these colors correct so I can actually figure out what the hell is going on here. I think my pain is making me realize I better make it simple for the person who might follow me. As it is this just isn’t cool. But I think I figured out the horn issue - there’s nothing connected to that spade connector on the backside of the horn assembly
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Sorry for multiple posts, but this just keeps getting crazier. I have a three-position switch located to the right of the steering column which is clearly an aftermarket add. It’s wired up to these red air horns that are mounted behind the front grille. What the hell is this and why? THESE I can get to sound with a horn button press now so someone assumed this was an upgrade.
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seems your PO decided to go for a custom aftermarket setup on their horns, hence disconnecting the original wiring as they would not use the stock horn connector... your chance to rebuild back to original and get rid of the aftermarket stuff...
A nice example of how you train your diagnostic skill on electrical wiring. I started out with little knowledge, and today feel much more confident in reading diagrams, diagnosing issues and fixing faults. The horn wiring is a good and simple example to start with.
A nice example of how you train your diagnostic skill on electrical wiring. I started out with little knowledge, and today feel much more confident in reading diagrams, diagnosing issues and fixing faults. The horn wiring is a good and simple example to start with.
Hi
This is the wiring on mine before re installing it into the car .
She is a September 1973 Right hand drive Csi. ( I think some of the wiring changed at the factory from 1974 on )
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Yep, you are exactly right. This has been an instructive evening. So I think what I’ve discovered is that someone added the air horns but installed a 3-position switch so moving it to the left would allow for one set of horns with button push and to the right would allow the original set of horns. Middle position disengages both. No idea why this was the decision, and in order to add this switch they moved the hazard light up to the upper half of dashboard and put this switch in the hazard light position. To add to the confusion at a later point someone disengaged the connection between the horn button and the switch so neither would work. Would love to understand the course of events that led to this outcome. Well, regardless it taught me something about how to figure out the wiring and inspired me to correct the incorrectly-colored wires as well as we all had a good discussion of various horn options including rebuild vs red vs black Hellla aftermarket ones from Amazon.
In case you want to re-install the bronw-yellow wire, there is a shop in Germany stocking it:
https://shop.kabelknecht.de/p/flry-2-5qmm-10m-ring-braun-gelb
https://shop.kabelknecht.de/p/flry-2-5qmm-10m-ring-braun-gelb
The hazard switch was moved to the dash rail on all 3.0 coupes from underneath on the 2800.
@HB Chris - ok, that's good to know. THe owner's manuals that came with my car are for the 2800 and then have small <20-page "additional" manuals to address the 3.0 and 3.0 CSi changes, but there isn't any note made of these changes to the dash. So if the hazard light is in its "correct" location on the dash rail, what would normally have been sitting in that right lower spot (just to the right of the orange button) where the PO placed a three-position switch? This is an area that doesn't tend to show up well on photos from any prior auctions, since the steering wheel sort of covers it up.
Europe got the 3.0 before the USA and production of the 72MY was July of 71 for the US and that might be why some euro coupes still had it underneath.